Canning method for tomatoes and the like



I Patented Apr. 24, 1951 CANNING METHOD FOR TOMATOES AND THE LIKE William J. Emmons, Oakland, and Bernard S. Gallagher, Piedmont, Calif, assignors to Salter Machine 00., Oakland, Calif a corporation of California No Drawing. Application July 23, 1945,

Serial No. 606,714

7 Claims.

1 This application is a continuation-in-part or our application Ser. No. 541,098, filed June 19, 1944, entitled Canning Method for Tomatoes and the like, now abandoned.

Our invention relates to a process for the canning of fruits and vegetables, and particularly to an improved method for obtaining a firming thereof and for handling the firming agent in dry form.

An object of our invention is to provide a practical method for using calcium chloride in dry form in the process of canning foods.

Another object of our invention is to provide an improved commercial method of retaining uniform firmness of tomatoes throughout and foladd sodium chloride (table salt) to restore a satisfactory flavor to the product. However, in connection with the use of table salt, the art teaches that the effect of table salt on solids in canning tomatoes is to soften and disintegrate the fruit and to reduce the drained weight of the contents. makes possible the use of calcium chloride to protect the firmness of the tomatoes and also the use of sodium chloride as a flavoring Without the usual resulting loss of drained weight ordinarily caused by the softening effect of table salt.

Heretofore the calcium chloride has been added in two general ways: I

' Where added as a solution with the fruit juice the calcium salts do not give a uniform result because they are partially spent in reaction with the acids in the juice before they get to the fruit. Also it is difficult to maintain the solution at a uniform density. Furthermore there is no known method of accurately dispensing the proper quantity of the solution to the cans as they move along the automatic canning lines. Unavoidably, the product lacks uniformity under the prior practices.

Another important factor contributing to this lack of uniformity is the varying amounts of the solution added to the cans to fill them, depending upon the volume of the solid contents already in the can.

For example, in an extra standard pack of tomatoes which the canner decides should weigh The following described method about 30 ounces for a 2 size can, the solids would weigh about 20 ounces going into the can. The other 10 ounces is the solution. The going-in weight will unavoidably vary 'over a range of an ounce or so each Way, which means that the solution in the cans will vary several ounces. If there is too much solution, the Federal Food and Drug regulations are violated. If too little, the calcium is not sufiicient to accomplish its firming effect. The product is not uniform. Also in the case of a solid pack, where no juice is usually added, a solution cannot be used to introduce the calcium.

The only other way heretofore developed for introdpcing the calcium was in tablet form, as is disclosed in such trade publications as Canning Age of February, 1942, page 91. The Martin Patent No. 2,333,873 points out the shortcomings of that method of introducing the cal cium. The present invention overcomes all the shortcomings of the prior art.

Until the present invention the art had regarded the addition of the calcium chloride salt in dry form as being impossible. See for example the Canner, vol. 90, No. 2, pages 12 and 13, of December 16, 1939; and the Martin patent.

Our invention has to do with the discovery of an improved method of introducing the calcium chloride (CaClz). By means of our method commercial canners have been able to raise their pack to a premium grade, while other of the same kind of fruit, packed simultaneously by older methods, was not so raised. We shall discuss our invention in connection with tomatoes, for purposes of illustrating its application to fruits and vegetables, as required by Revised Statutes, section 4888. It is understood, however, that variations in the showing made by the said description may be adopted within the scope of the invention as set forth in the'claims.

Broadly our invention covers the process for dispensing calcium chloride in dry form in a cannery packing line or other location where atmospheric conditions are such as have heretofore made the use of calcium chloride in dry form seem impossible.

In a packing plant using, for example, an exhaust box, sealer, cooker and cooler We may obtain the advantages of our new method either by first putting the tomatoes in the can, then addinga measured amount of the calcium chloride as a dry solid in subdivided or tablet form so that it can be dropped onto the material in the can, or the calcium chloride may be dropped into the can before the tomatoes are put in. Calcium chloride, as is well known, is extremely hygroscopic, and if left exposed to the ordinary atmosphere, it quickly takes up moisture from the atmosphere and dissolves in the water so taken up; and this is particularly true in the humid atmosphere thereby preventing the properfiow of: material.

through the ducts provided for that purpose. The present invention makes possible the use of dry calcium chloride in the cannery, by maintain.-

ing it dry until it is to be used. We keep itdry by protecting it from atmospheric moisture.

In a modern cannery, the processing steps are continuous and automatic. The problem, therefore, has been not only that of maintaining the dry calcium chloride dry, but involved, in

addition, the problem of automatically feeding it. in. measured amounts into thev cans. With this in.view, we prefer to. store the dry calcium chloride in. subdivided form in a dispenser, housed within a chamber, from which. it. can

be. servedas required, with an atmosphere prevailing within the dispenser and chamber which has. a relative humidity low enough to keep it dry. The preferred. way of producing, the desired result is to have a suificiently dry atmospherewithin the dispenser and the chamber,

whether such atmosphere be air or other gas. For example, any suitable method of heating may be used, to produce a, dry atmosphere within. the dispenser and. chamber. Perhaps the simplest. is an electric heating element. All that is, neededis to have the relative degr'e'fof humidity not higher than. the maximum. effective for the purpose, and it isv preferably lower than such maximum asafactor of. safety. A mean temperature of the air withinthe container. as

high as 130 F; to 140 F. is effective under. ordinary cannery conditions of operation. This temperature range is. merely an example andmay vary with different locations.

A. dispenser and. chamber mechanism of suitable type. can. be provided to feed, pre-determined, measured amounts of the dry calcium chloride from an outletin the chamber into the cans, jars, or the like, when it is. desired that such operation be automatic.

The original container in which calcium chloride is shipped and/or stored, or any suitable bottle or airtight container, will, when properly sealed or stoppered, maintain the calcium chloride dry by protecting it from extended contact with the atmosphere.

After we add the dry calcium chloride. to the tomatoes in. the can, we may proceed by pass.- ing the tomatoes through the exhauster,.then adding sodium chloride (NaCl), closing the can, and then passing it through the cooker and the cooler. The sodium chloride. is useful as flavoring and serves to overcome the bitter or foreign flavor imparted by the calcium chloride, which was introduced to keep the tomatoes from breaking up during the cooking operation. Although theoretically the sodium chloride counteracts the calcium chloride and would be.

expected with the heat of cookingto break down the'fruit, we have'discovered that by having addedthecalcium chloride dry and in a uniformly measured amount before the table salt (NaCl),

that thecalcium chloride hasihad a maximum.

reaction with the acid present in the fruit so it supports the cell structure during the heating and cooking steps and produces a canned prod.- uctwith a very firm characteristic. With the calcium salt put in the can ahead of the table salt,- thedestructive-eifect of the latter on the cell structure nullifiedand'a product is obtained down the line.

of result. Furthermore, there is the difficulty of measuring accurately the amount of calcium solution introduced into each can as it speeds By accurately measuring the dry calcium salt and introducing it. into the can in dry form a uniform reaction is, assured; The quantity of. sodium chloride added later will vary with the quality of the. particular. fruit,. but a. good general ratio is about four times. the amount of'calcium chloride. The table saltalso. is. best introducedin dry form in carefully meas-. ured amounts.

The time interval between adding the. dry. cal:- cium salt and the dry sodium chloride will depend on several factors: for example, it should be long enough for the calcium. chloride to act on the fruit to get the firming and the cellstructure fortified before the sodium chloride reaches it. The calcium chloride, is very quick. to dissolve and it will spread throughout thefruitvery quickly particularly the fruit is warmed as in the exhauster. It is desirable to get the ca1= cium chloride spread throughout the fruit cells before the sodium chloride appears.

To accentuate the delay it may in some. cases be advisable to encase the measured amount. of table salt (NaCl) in a capsuleor coating which Will not dissolve immediately uponits introduction into the can. Preferably this. capsule isone which requires heat to melt it. before itcan re.- lease the salt.

Our invention has application as wellito the more recent method of canningwherev the ex: hausting step is dispensed with and a. vacuum pack is used. In this modification it is important in carrying out our discovery thatthe sodium chloride and the calcium chloride be add.- ed separately in dry measured amounts. If no capsule is used for the sodium chloride then we. preferably deposit it in the opposite end of the. can from the calcium salt. Thus, the dry NaCI may be put in the can, then the. fruit, then the. dry CaClz on top of the fruit. Thedry caclz, being separated from the NaCl', has a chance to. go to workv out of .the. presence of. the. NaCI. and quickly dissolves and spreads throughout. the bulk. of the fruit, firming it up before. the NaCl' can get at it. It is. optional which salt is put in the bottom of the can, althoughwe have found quicker spreading results from. putting the CaClz on top.

Our invention is also applicable to the vacuum standard pack, that is, a pack in whichjuice of the fruit is added. In this. case, the dry CaCl; in a measured'amount is introduced into. the can, then there is a time. interval before. the NaCl is introduced or a capsule maybe used.

fol'iowed by vacuum sealing of the can, then cooking and cooling. The capsule dissolves in.

it is in the can, then have a time interval for it to dissolve and spread throughout the fruit to firm up the tissue before the dry sodium chloride is added and the can sealed in a vacuum sealer or othe closing machine. Here again the time interval may be obtained by use of a capsule for the NaCl.

It is to be particularly noted that the process herein described for obtaining uniformity and for improving the percentage of soilds in the canned product has proven positive and universally dependable. And it will be further noted that while the application of the process as herein more specifically set forth is that which has been used in the cannin of tomatoes, the same may be effectively applied to the preparation of other fruits and vegetables which tend to disintergrate during canning.

An additional benefit made possible by the invention has to do with the matter of flavoring the tomatoes.

As used in the claims the word can is understood to mean any container, whether made of metal, wood, glass, paper, plastic or synthetic material.

As used in the claims the words calcium salt are understood to mean any calcium salt in a form suitable for accurate dispensing in measured amounts and which acts to firm the fruit or vegetable cell structure.

As used in the claims the words sodium chloride are understood to mean any flavoring medium which is suitable to overcome the flavor imparted by the calcium salt. It may or may not be NaCl.

We claim:

1. In a process for canning fruits and vegetables the steps of placing a charge of sodium chloride in the can, filling the can with material chosen from the class consisting of fruits and vegetables, dumping on top of said material a measured charge of dry calcium chloride, closing said can,

charge opening at the bottom of a dispensing chamber, maintaining a dry atmosphere in said chamber, maintaining said calcium chloride in a hopper in said chamber measuring in said chamber a predetermined amount of said calcium chloride from said hopper, dropping said measured calcium chloride from said chamber through said discharge opening as each container passes directly below said opening, then dropping a charge of sodium chloride into said containers in such time relation to said calcium chloride that said calcium chloride reacts to harden said tomatoes before said sodium chloride reacts with said tomatoes, affixing lids to said containers, and then subjecting said containers to a cooking process.

6. A process for employing calcium chloride in firming canned fruits and vegetables which comprises the steps of stabilizing dry, granular calcium chloride within a chamber at the locus of use, maintaining within said chamber an arid atmosphere to prevent the transfer of water from the atmosphere surrounding said chamber to the solid contents housed therein, measuring a charge of said calcium chloride, dropping it directly from said arid atmosphere into the can containing the material being canned, adding to said can sodium chloride after said calcium chloride has reacted with said material to forestall and prevent softening, and then cooking said material.

7. In the canning of fruits and vegetables to be treated with calcium chloride and seasoned with sodium chloride, and process to increase the resistance of fruits and vegetables to the softening effects of sodium chloride and of heating, which consists of storing dry granular calcium chloride in a dispenser housed within a chamber, maintaining Within said chamber an arid atmosphere, placing material chosen from the class of fruits and vegetables into a can which is to be sealed, dropping on to said material a measured and subjecting its contents to a cooking temperature.

2. In a process for canning fruits and vegetables fruits and vegetables, dumping on top of said r material a measured charge of sodium chloride, closing said can, and subjecting its contents to a cooking temperature.

3. A process for obtaining firm and seasoned canned fruits and vegetables which incorporates into the normal canning operation the step of adding dry granular calcium chloride to the material being canned before said material is seasoned or cooked, waiting for a time interval to elapse, adding sodium chloride thereto, and then cooking said material.

4. In a process for canning vegetables and fruits, the steps of subjecting uncooked material chosen from the class consisting of fruits and vegetables to the reaction of a measured charge of dry granular calcium chloride and, when said reaction has extended substantially throughout the bulk of said material, adding a measured charge of sodium chloride to season, and then cooking said material.

5. In the canning of tomatoes, the method of adding dry granular calcium chloride in predetermined amounts directly to containers filled with said tomatoes, which comprises passin said filled containers in a single fi e beneath a disamount of said calcium chloride through a discharge port at the bottom of said chamber which extends directly from the arid atmosphere within the said chamber to a point above the desired locus of disposition of said calcium chloride, waiting an interval of time, adding a measured charge of sodium chloride, and subsequently cooking said material.

WILLIAM J. EMMONS.

BERNARD S. GALLAGHER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 895,377 Kunz Aug. 4, 1908 1,887,073 Suppiger Nov. 8, 1932 1,998,179 Wolf Apr. 16, 1935 2,031,243 Wolf Feb. 18, 1936 2,186,003 Blair Jan. 9, 1940 2,214,419 Jones Sept. 10, 1940 2,326,276 Avekidian Aug. 10, 1943 2,333,873 Martin Nov. 9, 1943 OTHER REFERENCES Canning Age, Feb. 1942, page 91. Calcium Firming of Canned Tomatoes. The Canner, vol. 90, No. 2, pages 12-13, published Dec. 16, 1939. The Efiect of Calcium Salts in Canning Tomatoes. 

1. IN A PROCESS FOR CANNING FRUITS AND VEGETABLES THE STEPS OF PLACING A CHARGE OF SODIUM CHLORIDE IN THE CAN, FILLING THE CAN WITH MATERIAL CHOSEN FROM THE CLASS CONSISTING OF FRUITS AND VEGETABLES, DUMPING ON TOP OF SAID MATERIAL A MEASURED CHARGE OF DRY CALCIUM CHLORIDE, CLOSING SAID CAN, AND SUBJECTING ITS CONTENTS TO A COOKING TEMPERATURE. 